Some movies are good, some are bad, some are just ok, and a very select few start out good, get you on board, then slowwwwwly get worse and worse until you finally stop caring about them. Here are 8 movies that fall into this extremely specific category:

1. The Patriot (2000)

Hot off the heels of Braveheart in the once-thriving "Mel Gibson slaughters a bunch of cartoonishly-evil British dudes" genre, 2000's The Patriot starts out as an interesting portrait of a farmer who just wants to settle down after living through the atrocities of the French and Indian War, then after about twenty minutes, it just goes full-on "fuck it" and it turns into two hours of Mel Gibson butchering dudes with a tomahawk.

Plus! If you thought the Brits in Braveheart were hilarious caricatures of mustache-twirling action-movie-villains (did you know there's no historical account of Longshanks ever declaring 'Prima Nocte'?), then buckle up for the bad guy in The Patriot, who not only shoots Mel Gibson's ten-year-old son, but also BURNS A CHURCHFULL OF INNOCENTPEOPLEALIVEFOR NO REASON (despite the fact that British generals essentially lost the Revolutionary War because they were too gentlemanly.)

2. The Lost World (1997)

Ian Malcolm! Dr. Hammond! DINOSAURS! Woohoo, we get to watch MORE Jurassic Park!! Wait, why is that happening? Why is that happening?? Who are these people? Why are these people doing that?? Oh man, this isn't Jurassic Park. This SUPER isn't Jurassic Park.

OH MY GOD, Jeff Goldblum's daugher just GYMNASTICS-KICKED A RAPTOROUT A WINDOWANDJEFFGOLDBLUMQUIPPED "You got CUT from the team??" And now it's a Godzilla movie. Oh cool! Now the actual filmstrip is vomiting.

3. Captain America (2011)

Weird how this movie started as a cool, stylized time-period origin story, then for the entire second half of the movie, there's just this giant COUNTDOWN TO AVENGERSMOVIE clock in the center of the screen? Ballsy artistic choice.

Oh! For the record, I'm talking about the film Captain America: The First Avenger. You know, what we all called it.

4. Prometheus (2012)

Ahh, the film that launched a thousand friend-arguments. Personally, I really, REALLY wanted to like this super-slick-looking sci-fi adventurethingy, but it just bludgeoned me into apathy with plothole after plothole (How do the two guys get lost when they have intricate 3-D maps of every square inch of the cave? Why is the one dude afraid of a dead body, then suddenly tries to pet a weird alien snake thing? Why didn't Charlize Theron run SLIGHTLY TO THESIDE???)

That surgery scene, though, wow. I would've watched that on repeat 6 times with no explanation or follow-up and I would've come out of the theater content, and on speaking terms with more friends.

5. 28 Weeks Later (2007)

HOLYCRAP the opening scene in this movie is incredible -- it really should've just ended after the initial zombie attack (or "fast diseased people" attack, technically) and just won the 'Best Live-Action Short Film' Oscar.

Instead, this Boyle-less outbreak-sequel proceeds to gradually chip away at your sense of giving-a-shit, one plothole at a time, by first having two children easily escape a military-quarantine, then those children instantly find their presumed-dead mother who's still alive because of a quirky genetic condition, then the mom infects the husband who abandoned her, then that husband somehow gets loose inside the quarantine and infects a million people instead of just getting sealed off and shot, etc etc and boom! Generic, obligatory copy of the first movie (with a really cheesy, faux-intense final shot).

I almost perversely wish there'd been a 28 Months Later that started with another military quarantine and all the people being like "Ok, THIS time we got it under control - AAAWWWWWCRAPPPNOTAGAIN" and like, a dog starting another outbreak then they just reuse the same footage from the first two movies.

6. Hollow Man (2000)

This Paul Verhoeven-directed thriller received almost unanimously-negative reviews, but I remember finally seeing it on HBO and being really into it at first; it starts as a movie about scientists dealing with a potential invisibility serum and all the moral and physical implications of having that power, then eventually, Kevin Bacon just goes conveniently insane and goes on a weird raping-and-murdering rampage and it's an hour of, like, Deep Blue Sea but with an invisible Kevin Bacon shark.

7. The Matrix Reloaded (2003)

The first Matrix was a groundbreaking technical achievement with a half-dozen unforgettable scenes and a plot that wraps up neatly and completely. When they inevitably forced a sequel, it was easy enough to cling to the hope of "well, even if this makes no sense and isn't necessary, at least there'll be a bunch of cool weird shit happening," but mid-movie, this excitement eventually yields to an impending sense of "wait - this really makes no sense and isn't necessary." Then the ultimate climax is a sagely hologram-man reciting a thesaurus, exactly what the first movie was missing.

(P.S. - The third Matrix doesn't qualify for this list, because the badness starts WAY before 20 minutes. It might not even last 20 seconds -- it actually starts being shitty sometime in the middle of the production company logos.)

8. Hancock (2008)

Two word movie pitch: ALCOHOLICSUPERMAN. What a perfect idea! Just let it play out, and don't invent a supercomplicated mythos with Charlize Theron and AHHH crap now Jason Bateman's improving his public image aaaand now it's turning into a regular action movie. Dag nabbit. We almost had it there.

On the plus side, the presence of Jason Bateman allowed us to finally come to grips with the fact Arrested Development was over with, so we could finally begin the healing process of frantically refreshing the entire internet every second in the hopes that a new AD movie rumor would leak out and make us happy even if it was totally made up.

I suppose now I need a big, overriding point to conclude this post, but can't really think of anything. OR IS THIS A META-JOKEABOUTTHISARTICLEITSELFGETTINGSHITTYAFTER 20 MINUTES??? Answer, sure, I definitely planned that.

Other movies that turn shitty after 20 minutes? Leave 'em in the comments!